Figure 1.

Cefazolin dosing and blood sampling schedules for patients undergoing cardiothoracic surgery with cardiopulmonary bypass (CPB). The down arrows (↓) represent intravenous administrations of cefazolin with doses (1 or 2 g), and the arrowheads (▼) represent blood samplings. The horizontal box represents the duration of CPB. The times of skin incision and would closure are indicated by up arrows (↑). In a patient whose course of surgery was complicated before CPB initiation, the second dose of cefazolin was administered before the initiation of CPB